PIA ZADORA, film actress and singer of the "Clapping Song" on Elektra Records, had been frightfully busy with interviews on National Public Radio and other broadcasting outlets and buying chocolates.

The last is not generally known. It slipped out.

"Well, anybody can look good at lunch if he's been stuffing chocolates all morning," I said gallantly.

"I'll just have the mushroom soup," she said, "and maybe some strawberries later."

But note, she did not try to weasel out of the Kron confession or try to pretend she only ate one mouthful. No. She had been bad, but she didn't try to squirm out of it. She sinned, as Luther might have said, bravely.

Zadora, who is famous mostly for being famous, does not let her manager, Tino Barzie, eat chocolate. He is a big boy, a one-time relief pitcher for the Red Sox, and sometime manager for Frank Sinatra and for Tommy Dorsey, and he is scared to death of her, chocolate-wise.

Pia Zadora had vanished briefly to please a photographer, who upheld the honor of the trade by wanting her to be virtually any place except where she already was.

"If she comes back," said her manager, "for God's sake tell her YOU ordered the Black Forest cake."

She came back, and the manager had bolted the cake down in three seconds but the waiter didn't get the plate off the table soon enough.

"He just had an apple," I said, wondering if the press really should get involved in these sorts of lies.

Her eye went straight to a chocolate smudge on her manager's plate. Probably it should have been explored, why she doesn't let the man eat chocolate, but life is short and you can't do everything.

"You look awfully young," it was pointed out to her.

"I'm 26. But thank you. It's odd, a woman always likes to be thought younger than she is, no matter what her age. It will come in handy later on."

(Her manager confided, later on, that her husband, who presides over a conglomerate that owns the Riviera Hotel in Las Vegas among other properties, has her pegged right: "She looks like 13 but really is 88.")

"I think it would be awful if we were all alike," she said, having given a few wise observations on child-raising, a subject she rather enjoys, probably since she has no kids yet but is looking forward to them.

"Take women. Now in work a woman ought to be equal, but not in marriage. The man ought to be the strong one."

"That's what bossy women always say," I ventured.

"Well, I am bossy. So is my mother. My wonderful father, Alfons Schipani, is a musician and utterly helpless in front of a paintbrush or anything around the house. My mother can paint up a storm and do all those things. My father first played in Carnegie Hall when he was 13. He's a violinist, and has played with the Philharmonic and the Met and so on.

"He has glasses this thick and can't see a thing. Once he was rowing my mother and me and the poodle out in New York Bay when the wind came up and we started drifting out to sea. Poor man. My mother and I and the poodle all started getting hysterical. We got back, somehow." (That poor poodle has since died and she now has an akita but can't keep it with her with all this traipsing about; it stays with her mother in New York).

"I studied voice at the Juilliard School," she went on, daintily trying a spoon of soup, "because I had an aunt and a grandmother who both sang in opera. My mother was wardrobe mistress for the New York City Opera, and what with my father a musician too, I was surrounded by classical music through my childhood in Forest Hills and I was supposed to be preparing for a career in opera."

"You love the opera?" she was asked.

"I loathe opera. I liked it until I was a teen-ager. Then I turned to rock."

"Well," she was reminded, "you have most of your life ahead of you. You'll come back to Tannha user some day."

She cast a fishy eye at the soup. One had the strong feeling she had heard this or something like it ("My dear, Bach lasts" or "But don't you see, Mozart is forever" zub, zub, zub) once or twice before.

"I first played on Broadway when I was 6. From then on, it was one show or another or some project from then on.

"There came a time for my mother to stop being a stage mother, but she loves the theater and its people and has been divinely happy as wardrobe mistress and as far as I can tell everybody adores her.

"I was an only child. When you're little, you think it's too bad you're an only child, but now I think I was lucky. No, I didn't miss playing sandlot at all.

"I was insecure. Who isn't? I loved being on the stage doing my bit--I was the next to smallest child in 'Fiddler on the Roof'--and that gave me security, that I could get up there and perform. Though I was very shy off the stage.

"I have a friend who has two kids and she always says I was born with a silver spoon in my mouth, and everything always goes right for me. Well, it does, and I'm grateful. When you look around at the world, I can't believe how fortunate I've been.

"Of course, all artists are insecure. It's a marvelous feeling, up there on the stage, safe. You're there and the audience is way out there and there's communication."

"In the best theaters, the audience STAYS out there," it was suggested.

"Yes. But not necessarily in rock. I used to be out in the audience and just dash up there. They reach up. It's very nice."

"Probably it is. If you don't get killed," her questioner tossed in, just to let her know that he knows all about rock concerts.

"This place is nice," she said. "The Four Seasons. It's nicer than in New York, more intimate. The roof up there is so high. I don't like that. I like to be able to see it and know it's there keeping the rain out."

"I think squirrels are that way, they say many animals are. Want a nice snug hole to curl up in out of the weather," I tossed in, quite lost in the deplorable vision of Pia Zadora unable to curl up and be truly comfy at the Four Seasons in New York. Actually, the particular dining room we were in was about as intimate as RFK Stadium at hot dog time, all those people bolting down food. Though Pia Zadora worked daintily along at her soup.

"No, I don't dream of the legitimate theater," she said. "You learn your part, you realize that every night there's a new audience and you have an obligation to make the play new for them, whether it is or not for you. And, of course, you love the applause.

"But I find the movies Zadora's films have been "Butterfly," "Fakeout," and "Lonely Lady." These have all been backed by her husband, Rik Riklis. much more fulfilling. You don't hear the applause, but there's the excitement of seeing the rushes each night. And you're what, 100 times bigger than life. In closeups the camera catches the least expression, that of course would be lost in the theater. And I find it hard to think of life without singing."

I had heard--for people are quite vicious nowadays, especially toward a pretty little girl just trying to make her way--that in "Clapping Song" she just clapped.

"No, of course I sing. Goodness, that's an idea for you. Buy a record to hear Pia Zadora clap. They like the song very much in Europe. The Italians? Oh, well they are Latin, of course, aren't they? They like women. I never go out on the street alone, and besides most of them know I'm married and not free for dates or anything like that. Still, they like women and show it. The French also like women but they tend to sit there waiting for you to come to them."

"Pia," said her manager when she excused herself for a minute, "is the only woman I know who if she were alone in a room could start a war. Of course she's wonderful and all that, but let me tell you she's the worst person in the world to be in a sinking ship with. Listen, if we were traveling with her in a plane that started to crash, I'd get right up and find another seat." Pia returned, utterly safe, thank God, and said she only spends a few days a month at home in Beverly Hills, a few days in New York--she is always traveling about, as now, when she is on a 16-city tour to promote the clapping song in which, you remember, she sings.

Some people, especially the aged, think Zadora is the girl who keeps leaping naked into a fountain basin at Cannes during film festivals. Others complain she is not as good as Judith Anderson (at dramatic intensity, though at least her equal fountain-wise) or Marilyn Horne (as an agile singer) and this negative image held by some people, which very likely is some sort of paid conspiracy to damage her good name, has gone so far that one young woman asked her interviewer to find out who the hell Pia is and what she does, because all the young woman could find out was that Johnny Carson kept cracking jokes about her on "The Tonight Show."

Others have hinted, in the sleazy way these things are done, that she won the Golden Globe Award for best new actress because her husband somehow influenced the voting. When you get down to it, how many new actresses are there since Vivien Leigh, so why not Pia?

We live in a defamatory age. It turns out Pia was not naked, but had on a bathing suit ("you understand European bathing suits are not always like ours") and besides, that was only once. And in a different country and a long time ago.

She does love to buy clothes. She loves to shop. And she doesn't lie about this vice, which men judge harshly and the more harshly as they acquire wives and daughters, nor does she pretend she just shops for an aunt in a distaff house. No sir, bold as brass, she shops for herself and buys things like mad.

"Oh golly," one might cry, "you have been killing innocent animals," as she put on a fox fur coat.

"Well, they do keep you warm," she said, "and, honestly, they were already dead when I bought them."

Let's see now. There may be something wrong with that argument. But what the hell. She smiled and bounced off like a kitten to sign some record jackets.

Speaking of kittens, her mother is now wardrobe mistress of the Broadway musical, "Cats," in which everybody dresses in cat suits. For quite a while Pia thought it was "Katz," possibly about some nice old man in the garment district.

But, look, nobody can know absolutely everything.